Factionalism is when people inside one organisation — a party, a company, a school club — split into smaller groups and fight each other. The whole group is supposed to share a goal, but each small group starts caring more about beating the other small groups. You hear this word in politics, at work, and in long-running clubs. It is fairly formal; in easy talk people might just say they have split into camps. It is not the same as ordinary disagreement. People can disagree and still work. Factionalism is when the sides get names, pick leaders, and keep score. Though actually, a bit of this shows up in almost any large group. The word is usually a complaint, said by someone who thinks the fighting has gone too far and is hurting the whole.

派系主義；派系鬥爭